Scaffolding structure



June 8, 1965 R. E. STEWART, JR.. ETAL 3,187,833

SCAFFOLDING STRUCTURE Filed Oct. 2, 1963 3 Sheets-Sheet 1 INVENTORS.1905597 5. STEWARTJZQ. OIPLEAN B. RAP/ER ArmP/vEy June 1955 R. E.STEWART, JR., ETAL 3,187,838

SCAFFOLDING STRUCTURE Filed 001;. 2, 1963 3Sheets-Sheet a 29a 20 20INVENTORS- ROBE/P7 E. STEWART JR.

OELEAN B. RAP/2 BY w QW ATTOPNEY United States Patent 3,187,838SCAFFGLDING STRUCTURE 1 Robert E. Stewart, in, 8458 Periwinkle Drive,Euena Park, Calif, and Orleau B. Rapier, 8357 Golden, Paramount, Calif.

Filed Oct. 2, 1963, Ser. No. 313,223 10 Claims. (Cl. 182-144) Thepresent invention relates generally to scaffolding,

and more particularly to a scaffold that is adapted to be removablymounted in an encircling position on building structures such ascylindrical vessels, fractionation towers, chimneys, and the like, andmoved vertically relative thereto.

A major object of the present invention is to provide a scaffold thatencircles a structure of the type described which is supported from theupper portion thereof I and can be moved relative thereto without thenecessity of erection from the ground up, whereby the ground surfacesurrounding the structure is maintained in a clear condition and workcan be carried out thereon without interference.

Another object of the invention is to provide a scaffold that includes asupport forthe workmen, inside and/or outside the structure being Workedon, with the supports being adapted .to be moved concurrently upwardlyor downwardly as desired.

A still further object of the invention is to provide a scaffold inwhich a numberv of rectangular sections are removably connected todefine a multi-sided framework which surrounds a structure to be workedon and is maintained at a fixed distance relative thereto as theframework is moved upwardly or downwardly.

Yet another object of the invention is to provide a scaffold which isvertically movable relative to structures which are substantiallygreater in height than in width without recourse to grading a sloping,congested or unstable ground condition that may exist adjacent the baseof the structure. I j j A further object of the invention is to providea scaffold that can be easily and quickly erected as well asdisassembled, can be transported from one job site to another, assembledand dismantled by relatively unskilled personnel, provides optimumsafety in operation, and requires a minimum of maintenance attention.

Yet still another object of the present invention is to provide ascaffold that is assembled from a plurality of sections, at least aportion of which is adjustable as to width, with portions of thesesections being adapted to be formed into a configuration that avoidsoutwardly projecting fixtures on the structure, such as piping, walk 1ways, and the like.

These and other objects and advantages of the invention will becomeapparent from the following description of a first and an alternate formthereof, and from the accompanying drawings illustrating the same, inwhich:

FIGURE 1 is a top plan view of the first form of the scaffold mounted onthe upper portion of a cylindrical structure;

FIGURE 2 is a vertical cross-sectional view of the scaffold shown inFIGURE 1, taken on line 2-2 thereof;

FIGURE 3 is a fragmentary vertical cross-sectional view of the scaffoldshown in FIGURE 1, taken on line 3-3 thereof;

FIGURE 4 is a fragmentary'top plan View of two adjacent column platesremovably interlocked to maintain two scaffold sections in a desiredrelationship;

FIGURE 5 is a side elevational view of one of th scaffold sections usedwith the first form of scaffold;

FIGURE 6 is a side elevational view of -a scaffold positioner; 7

ice

scaffold sections used with the alternate form of scaffold.

With continuing reference to the drawings for the general arrangement ofthe first form of scaffold, it will be seen in FIGURE 2 to be movablymounted on an openended cylindrical structure A. The structure A whichcould be any one of a variety of types such as a chimney, fractionationtower, vertical vessel, tank, or the like, is supported on a foundationB.

The first form of scaffold C, as may best be seen in FIGURES 2 and 5,includes a base D formed from I- beams 10 arranged in the shape of aGreek cross. The outer end portions of beams 10 rest on the uppercircumferential edge 12 of structure A. Base D supports an upwardlyextending shell E, from the upper portion of which four arms F project.Shell E is temporarily attached to the top of closed end structures inlieu of base D. Arms F are in equal spaced relationship, and may berotated within shell E relative to the beams 19 so that they do not liein the same vertical plane therewith.

A number of sections G are provided, one of which is shown in detail inFIGURE 5. Eight sections G are joined in the manner shown in FIGURES 1and 2 which completelyencircle the structure A. Square and rectangularshapes can also be assembled using four sections G.

Sections G are each fabricated from a number of components which areremovably held together, whereby each section is variable as to thewidth thereof. Each section G is rectangular, and comprises twolaterally spaced vertical columns 14 which support verticallyspacedhorizontally disposed connecting plates H that can overlap, asshown in FIGURE 4. Bolts J engage vertically aligned bores 16 formed inthe plates H, whereby the sections G may be removably held together todefine the octagon shaped scaffold shown in FIGURES 1 and 2.

Four scaffold positioners K, the details of which are best seen inFIGURES 6 and 7, are supported from the lower end portions ofalternately spaced pairs of columns 14 (FIGURES 1 and 2); Thepositioners K serve to maintain the sections G in fixed, radially spacedrelationship relative to the exterior surface of the structure A as thesections are moved upwardly and downwardly relative thereto by meanswhich will hereinafter be explained in detail.

Each of the columns 14 has three vertically spaced, horizontal platformlevel indicators L projecting therefrom,

each of which terminates in a circular flange 18. Columns 14 also havethree horizontal, tubular reinforcing members M projecting therefromwhich are in vertical alignment with indicators L and spaced a fixedvertical distance therefrom, as may best be seen in FIGURE 5. Each ofthe platform indicators L is above one of the plates H, and one of thereinforcing members M is positioned a short distance below the plate.The reinforcing members M terminate in a flange 20 that is in verticalalignment with the flange 18. Flanges 18 and 20 are connected by boltsor other conventional fastening means to complementary flanges 13a and20:: that form a part of a spool piece N, as may best be seen in FIGURE5.

An elongate rigid tube 22 extends downwardly from eachreinforcing memberM, and the lower end of this tube is welded at 24 to one of the columns14. A number of horizontal, vertically spaced rigid members 26 arethereof and rigidly affixed to the tube.

welded or otherwise afiixed to each column 14.- and tube 22 (FIGURE 6)for reinforcing purposes. A number of plank supports are utilized withthe first form of scaffold which are shown in detail in FIGURE 9, andalso in FIGURES'l and'2.

Each support 0 comprises a vertical length of channel iron 28 from whicha second length of channel iron 3st projects in a direction normalrelative thereto, with the second length being disposed'downwardly fromthe upper end of the'first length a substantial distance. A third lengthof channel iron 32 extends between the second and first lengths 28 and30 respectively, in the manner shown in FIGURE 9 to reinforce the secondlength against a downwardly exerted load.

The first length 28 (FIGURE 9) includes first half portions 34 of pipeclamps. Second halfportions 36 of pipe clamps are provided which areconnected by bolts 38 to the first half portions 34. When the bolts 38are tightened, the clamp portions 34 and as are moved towards oneanother to permit the pipe portions to frictionally grip one of thecolumns 14 to hold the plank support 0 of whichthey form a part at afixed elevation on scaffold section G.

The upper portions of plank supports 0 are adapted to engage the column14 above the platform indicators L, with the upper surface 40 of thesecond channel length Elli-being substantially flush with the uppersurface of the indicator. By useof the plank supports 0, planks F can belaid thereacross to define platforms at three different levels, as maybest be seen in FIGURES 1, 2 and 5, to support workmen (not shown) whomay be doing maintenance, painting, or other work on the exterior surface of the structure A.

' -An upwardly extending lift plate 42 in which a number of spaced boltholes 44 are formed is aflixed to the upper end of each column 14 ineach section G, preferably as shown in FIGURES 4 and 5. The lift plates42 of two adjacent scaffold sections G lie in the same vertical plane,and are connected .by a tie plate 46 (FIGURE 4). The tie plate 46 isconnected to lift plates 42 by bolts 48 which extend through openings(not shown) in the tie plate and through'openings 44 in the lift platesto rigidly 96 to extend partially into the confines of tube 86.

The inner ends of the arms F are rigidly afiixed to tube 86 by boltingor the like, and these load arms rest on a spacer plate 98, which inturn is supported by end plate '74. A second spacer plate 1% ispositioned above the arms F and is in abutting contact with a thirdplate m2, which is welded by beads 1% to tube 86. A number of gussets 1%extend outwardly from the tube 86, with the lower ends thereof inabutting contact with the third plate 1%.

A four groove sheave 11% is rotatably supported inside the shell E on ashaft llltl. Shaft 11!) is rigidly supported inside shell E byconventional means. An opening 112 is formed in shell E, and atube 114extends therethrough, which is welded by beads "116 to the exteriorsurface of the shell, as best seen in FIGURE 3. V A flange II? is formedon the outer end of tube 114 which mates with a companion flange 129that has a second tube 124 extending therefrom. Flanges 118 and 129 areremovably connected by bolts 122..

In FIGURE 2 it will'be seen that each of the second cables 54 extendsupwardly and inwardly over one of the first sheaves do, then over thesecond sheave 7d, and downwardly therefrom through an opening (notshown) in one of the load arms F to one of the pulley blocks 58. Eachcable 54 extends upwardly from one of the pulley blocks 58 to engage oneof the third sheaves. after passing through an opening (not shown) inarm F on which the third sheave is mounted. After passing one of thethird sheaves '72, each cable 54 extends upwardly to engage one of thefourth sheaves :96, and then downwardly through the tube 86 to engageone of the grooves in the four groove sheave 168. After engaging thesheave 1%,

hold the two adjacent lift plates together. Each tie plate I 46 has anopening formed in the upper portion thereof through which a looped end50 of a cable 52 is connected by a shackle bolt. The two looped ends 50of each cable 52 are affixed to adjacently disposed tie plates 46, asshown in FIGURE 1, with the cable being connected at its center to asecond cable 54.

I Aplatform Q is provided which is of suchsize as to.

be vertically movable within the interior of structure A.

Four third cables 56 extend upwardly from platform Q,

each of which has a pulley block 58 affixed to the upper end thereof.

Four single groovefirst sheaves 60 are rotatably sup- .ported on shafts62 from bifurcated ends 64 of load arms F, and two parallel, laterallyspaced, longitudinally extending plates 66 project upwardly from eacharm, as may best be seen in FIGURES land 2. Two shafts extend between'each pair of plates 66 and rotatably support second and third singlegroove sheaves 7i and '72, re-

spectively.

An-1 pperend plate 74 is welded by beads '76 to the shell E (FIGURE 3).A second plate 78 disposed below plate 74 inside shell E is welded tothe shell by beads 8th..

Vertically aligned bores 82 and 84 are formed in plates 74 and 78. Aheavy tube 86 extends upwardly through bores 82 and 84 and 'is welded toplate 78 'by' beads 83. Four slots 90 are formed in tube 86, in each ofwhich a pair of lugs 92 is disposed on opposite longitudinal sides Eachpair of lugs 92 supports a shaft 94 therebetween on which a fourthsingle groove sheave d is mounted.

Slots are sufficiently wide and long as to permit sheaves each cable 54passes outwardly through the cable tubes I14 and 124 to another fourgroove sheave (not shown) which directs the cables in a verticaldirection to engage conventional power-driven drum means (not shown)whereby the cablesmay be drawn upwardly relative to the structure A, orby the weight of the load on the cables, and release of the brake on thepower-driven drum, permit it'to move downwardly relative to thestructure.

The detailed structure of the positioners K is shown in FIGURE 6, whichinclude an upper pipe clamp 126 from which a tube 1-28 extendsoutwardly. Tube 12% is with any one of the holes 132. When the bore inrod' 138 is so aligned, a pin (not shown) may be slipped through thisbore to hold the rod in a'fixed, non-rotatable position relative to tube128. Rod 138 supports a plate 140 on the end thereof, from which twoparallel, laterally spaced side pieces 142 project. Side pieces 142support a shaft 144 therebetween on which a wheel or roller 146is-rotatably supported. When the rod 138 is positioned in the desiredlongitudinal relationship with tube 128, the wheel 146 is disposedadjacent the exterior surface of the structure A or actually in contacttherewith, with the' four wheels serving to maintain the first form of'scaifold'C in a substantially fixed horizontal position relative to thestructure.

Each of the scaffold positioners K is mounted on the lower end, portionof one of the oolumns 14, as best seen in FIGURES 1 and 2, and each ofthe columns 14 has a small plate 148 welded or otherwise affixed to thelower end thereof. Each. of the plates 14% connects to the. upper end ofa conventional hold-down assembly 15%, the lower end of which is affixedto an anchor 152, or

' in the ground 154 surrounding the foundation B.

A second conventional cable hold-down assembly 156 is provided that hasthe upper end thereof connected to a lug 158 which projects downwardlyfrom the central portion of platform Q. The lower end of assembly 156 isafiixed to a suitable object 160 that is either driven into or embeddedin the foundation B. The hold-down assemblies 150 and 156 can bemanually adjusted to tension the cables forming a part thereof, and whenso tensioned, the cables cooperate with cables 52 and 54 to hold thescaffold C at a desired elevation relative to structure A.

The detailed structure of the spool piece N is best seen in FIGUREwherein it will be seen that the platform indicators L include heavymetallic tubes 162 having the flanges 13 mounted on the outer endthereof. An L- shaped member 164 is provided that has a vertical leg 166and a horizontal leg 168. The lower edge of leg 166 is welded to theupper portion of the tube 162. A gusset plate 170 extends between theupper surface of tube 162 and the lower surface of leg 168, and iswelded to the tube and leg by beads 172. A triangular web 174 extendsbetween the lower outer portion of tube 162 and an inner portion of thecolumn 14.

The spool piece N (FIGURE 10) includes a vertically extending plate 176,on the upper edge portion of which a tube 178 is Welded, with a secondtube 180 being welded to the lower edge thereof. The two tubes 178 and180 support flanges 18a and 20a respectively at the ends thereof, andthese two flanges abut against flanges 18 and 20, as previouslydescribed and as shown in FIGURE 5.

Two openings 182 are formed in plates 176, and two openings 184 areformed in plates 174. Two bolts 181 extend through openings 182 toengage eyes (not shown) formed on the end of a threaded tie rod 186. Abolt 187 extends through the opening 184 formed in plate 174 to engagean eye (not shown) on a threaded tie rod 188 that extends to aturnbuckle 190. Turnbuckle 190 engages threads on the tie rods 186 and188, and when the turnbuckle is rotated in an appropriate direction ittensions the tie rods to cross-reinforce the first form of scaffold C.An L-shaped member 192 extends upwardly from tube 178 that is of thesame structure as member 164.

Operation of the first form of scalford C is relatively simple. The baseD is mounted on the upper portion of the structure A as shown in FIGURE2 and inadvertent displacement thereof is prevented by clips 194 whichdescend from the lower outer end portions of the base D. The clips 194abut against the upper exterior surface of the structure A. The clips194 can be bolted or otherwise removably affixed to the structure Aduring the time the first form of scaffold is being used. When the baseD is thus disposed the arms thereof support the shell E in the mannershown in FIGURE 2.

The detailed structure of the elements associated with the shell E areshown in FIGURE 3. The sections G are disposed in upright positions toencircle the structure A, with the plates 148 of these sections restingon the ground surface 154. Bolts I are then caused to engage opening 16in the column plates H to hold the sections G in an .angularrelationship to define the octagonal frame shown in FIGURE 1.

The lift plates 42 are connected to tie plates 146 as previouslydescribed, with the tie plates in turn being connected to each twoadjoining tie plates by an upwardly extending cable 52. Each cable 52 isconnected to a second cable 54, which latter cable engages the firstsheave I 60, second sheave 7t pulley block 58, third sheave 72,

fourth sheave 96, and the four groove she-ave 108 to extend throughtubes 114 and 124 to power means for raising and lowering each of thecables 54. Cables 54 are con- 6 currently raised and lowered by powermeans (not shown).

The pulley blocks 58 are connected by cables 56 to platform Q, and ascable 54 is moved in a direction to raise the octagonal frame defined bythe first form of scaf fold sections G, the platform is raisedconcurrently therewith. Planks R are laid across supports 0 (FIGURE 9)in positions illustrated in FIGURE 1 to define three platforms S-1, S-2and 8-3 shown in FIGURE 2. By manipulation of cables 54, the assembledscaffold sections G may be raised or lowered to a desired elevationrelative to the structure A, whereby workmen thereafter supported on theplatforms S1, S-2 or S3 have access to the exterior surface of thestructure A to perform necessary work thereon.

When the sections G are assembled as an octagonal framework (FIGURES 1and 2) and have been raised to a desired elevation relative to thestructure A, the tie downs and 156 are adjusted to maintain tensionthereon to minimize movement of the assembled sections relative to thestructure. Transverse movement of the assembled sec-tions G relative tothe structure A is prevented by the scaffold positions K which are incontact with the exterior surface of the structure. As the first form ofsections G are moved relative to the structure A, the platform Q islikewise moved, from which Work can be performed on the interior of thestructure while work is progressing on the exterior thereof. It will beparticularly noted that when the first form of scaffold sections G areused as described, the area thereunder is substantially free ofobstructions whereby work can be carried out thereon by men notsupported on the scaffold.

Should the structure A have a nozzle 196 with a pipe 198 connectedthereto (FIGURE 1) that would interfere with upward and downwardmovement of the first form of scaffold C, one of the sections G can beremoved from the assembly, as shown in FIGURE 1. The sections G on eachside of the nozzle 1% and pipe .198 are connected by horizontal andvertically diagonal tubes 197. Tubes 197 are removably connected tocolumns 14 by pipe clamps (not shown). These horizontal and diagonallydisposed tubes 197 are alternately removed and replaced on the columns14 as the assembly shown in FIGURE 1 is moved upwardly and downwardlyrelative to the structure A.

A second form of scaffold section U is shown in FIG- URE 11 which issimilar to the first form G. However, scaffold section U is notadjustable as to width. Section U is used in the same manner as thefirst form thereof and serves the same purpose.

Each scaffold section U includes two laterally spaced, parallel columns21% that have lift plates 212 on the upper ends thereof and plates 214on the lower ends of the columns. Circular plates 213 are mounted oncolumns 210 that are structurally identical to plates H. Columns 21%)are connected by cross pieces 216, the ends of which are Welded orotherwise permanently connected to the columns. The cross pieces 216 arereinforced by reinforcing means 213, which are preferably tubular.Platform indi caters 22d extend between the columns 219 and serve thesame function as indicators 164 in the first form of section.

The use of the second form of scaffold section U is the same as thefirst form thereof, and accordingly its mode of operation need not berepeated.

Although the present invention is fully capable of achieving the objectsand providing the advantages hereinbefore mentioned, it is to beunderstood that it is merely illustrative of the presently preferredembodiments thereof and we do not mean to be limited to the details ofconstruction herein shown and described, other than as de fined in theappended claims.

We claim:

1. A platform supporting scaffold adapted to substantially encircle astructure of greater height than Width and be moved vertically relativethereto, including:

(a) a plurality of generally rectangular rigid sections,

each of which comprises two parallel, laterally spaced columns, andreinforcing means extending therebetween;

(b) a plurality of horizontal plates extending outwardly from saidcolumns and being of suificient size that said plates on said columnswhich are most adjacent to "one another have plate portions that overlapone another, with said overlapping plate portions having a plurality ofspaced openings form-ed therein, at least a part of which openings arealignable with one another; and

(c) a plurality of elongate rigid members that removably engage saidopenings which are aligned with one another for holding said sectionstogether;

((1) second means for holding said sections in said multi-sided frame atsubstantially fixed radial distances relative to said structure;

(e) third means for defining at least one horizontal platform;

(f) fourth means for removably supporting said third means from saidsections; and

(g) fifth means for concurrently raising and lowering said sections whendefining said multi-sided frame relative to said structure to permitperformance of Work on the exterior surface thereof by personnelsupported on said third means.

2. A scaffold as defined in claim 1 wherein at least a portion of saidreinforcing means in said sections is adjustable to provide sections ofsutficient width as to encircle said structure when said sections definesaid multi-sided frame.

3. A scaffold as defined in claim 1 wherein at least a portion of saidreinforcing means in said sections is adjustable, with each of saidreinforcing means that is adjustable including:

(a) a plurality of vertically spaced, horizontal, tu-

bular members that are in longitudinal alignment and extend inwardlytoward one another from said columns;

(b) a plurality of flanges mounted on the inner ends of said tubularmembers;

(c) a spool piece of desired width comprising a plurality of horizontal,vertically spaced tubes that are horizontally alignable with at least aportion of said tubular members, and a plurality of companion flangesmounted on the ends of said tubes which can be placed in abuttingcontact with said flanges on said tubular members; and

(d) means for removably connecting said flanges on said tubular membersto one another to provide a scaffold section of a first width and saidflanges on said tubular members to said companion flanges on said tubesto provide a scaffold section of a second width.

4. A scafl'old as defined in claim 1 wherein said secmeans comprises aplurality of planks, which when laid side-by-side define said platform,and includes:

(a) two vertically disposable first lengths of a rigid material; (b) .aplurality of pipe clamps that removably sup port said first lengths fromtwo of said columns which are adjacently disposed; and

(c) two second lengths of rigid material that extend inwardly towardssaid structure from said first lengths, which second lengths removablysupport said planks thereon to define said platform.

6. A scaffold as defined in claim 1 wherein said fifth means includes:

(a) a vertically extending hollow shell;

(b) a base for supporting said shell on the upper portion of saidstructure;

(0) a multi-groove sheave rotatably supported in said shell;

((1) a plurality of single groove sheaves rotatably supported from saidshell;

(e) a cable tube in communication with an opening in said shell;

(f) a plurality of cables extending through said tube to engage saidmulti-groove sheave and extend upwardly therefrom to engage said singlegroove sheaves and then extend downwardly towards said sections; and

(g) means for connecting the lower ends of said cables to the upperportions of said sections, with said sections being raised and loweredas said cable is moved outwardly and inwardly relative to said cabletube.

7. A scaffold as defined in claim 1 wherein said fifth means includes:

(a) a vertically extending hollow shell;

(b) a base for supporting said shell on the upper portion of saidstructure;

(c) a plurality of power driven drums supported from said shell;

(d) a plurality of cables wound on said drums; and

(e) means for connecting the lower ends of said cables to the upperportions of said sections, with said sections being raised or lowered assaid drums are rotated.

8. A scaffold as defined in claim 1 wherein said fifth means includes:

(a) a plurality of lifting plates affixed to the upper ends of saidcolumns;

(b) a plurality of tie plates extending between each two adjacentlydisposed lifting plates;

(0) means for removably afiixing said tie plates to said two liftingplates;

(d) a plurality of first cables, the ends of each of which are connectedto two adjacently disposed tie plates; 7

(e) a plurality of second cables, the lower end of each of which isconnected to a center portion of one of said first cables;

(f) a base in the form of a horizontally rigid cross that is supportedon the upper extremity of said structure;

(g) means for removably holding said cross on said structure;

(h) a hollow shell extending upwardly from said cross; a

(i) a multi-groove sheave rotatably, supported in said shell;

(1') a cable tube extending outwardly from said shell and incommunication with an opening formed therein; 7

(k) a platform horizontally disposed inside said structure and of suchcross: section as to be vertically movable therein;

(l) a plurality of third cables extending upwardly from said platform; 7

(m) a plurality of pulley blocks mounted on the upper ends of said thirdcables that are aflixed to said platform;

(n) a plurality of horizontal arms extending outwardly from said shell;

(0) a plurality of first sheaves rotatably supported on said arms;

(p) a plurality of pairs of second and third sheaves, with each of saidpairs being disposed above one of said arms;

(q) means for rotatably supporting each of said pairs of second andthird sheaves above each of said arms;

(r) a plurality of fourth single groove sheaves disposed in the upperportion of said shell; and

(s) means for rotatably supporting said fourth sheaves from said shell,with each of said second cables extending upwardly to engage one of saidfirst and second sheaves, then downwardly to engage one of said pulleyblocks, then upwardly to engage one of said third and fourth sheaves,then downwardly to engage one of said grooves in said multi-groovesheave, and then outwardly through saidcable tube, with said pluralityof cables when concurrently moved inwardly or outwardly through saidcable tube concurrently raising and lowering said sections on theexterior of said structure and said platform situated within theconfines thereof.

9. A multi-platform supporting scaffold for encircling a structure ofsubstantial height and adapted to be moved vertically relative thereto,including:

(a) a plurality of rigid rectangular sections, each of which includestwo parallel, laterally spaced vertical columns;

(b) a plurality of vertically spaced, horizontal, tu-

bular members that are in longitudinal alignment and extend inwardlytoward one another from said columns;

(c) a plurality of flanges mounted on the inner ends of said tubularmembers;

(d) spool pieces of desired width comprising a plurality of horizontal,vertically spaced tubes that are horizontally alignable with at least aportion of said tubular members, and a plurality of companion flangesmounted on the ends of said tubes which can be placed in abuttingcontact with said flanges on said tubular members to attain a pluralityof available horizontal widths of said sections;

(e) means for removably connecting said flanges on said tubular membersto said companion flanges on said tubes to provide scatfold sections ofvarious widths, with each of said widths being dependent upon thelengths of said spool pieces;

(f) variable length reinforcing means for maintaining each of saidsections in a rectangular configuration of desired width;

(g) first means for removably attaching a plurality of said sectionstogether to define a multi-sided frame which encircles said structure ata substantially fixed radial distance therefrom;

(h) a plurality of platforms supported from said sections; and

(i) second means for concurrently raising and lowering said sectionswhen defining said multi-sided frame relative to said structure topermit performance of work on the exterior surface thereof by personnelsupported on said platforms.

10. A scaffold as defined in claim 9 wherein said second means includes:

(a) a vertically extending hollow tube;

(b) means for supporting said tube on the upper portion of saidstructure;

(0) a plurality of vertically disposed sheaves circumferentially spacedabout said tube and positioned in alignment with vertically extendingslots formed in said tube;

(d) means for rotatably supporting said sheaves from said tube;

(e) a plurality of rigid arms that extend outwardly from said tube andare in substantially the same vertical planes as said sheaves;

(f) a plurality of sets of first, second and third sheaves rotatablysupported on said arms;

(g) a plurality of pulley blocks afiixed to the interior surface of saidstructure; and

(h) a plurality of cables that extend upwardly through said tube toengage said sheaves rotatably supported thereon, which cables thenextend downwardly over said third sheaves to engage said pulley blocksand thereafter pass upwardly over said second and first sheaves to againextend downwardly to a point where the lower ends thereof are afiixed tosaid sections, with the portions of said cables in said tube when moveddownwardly relative thereto raising said sections, and with saidportions of said cables in said tube when moved upwardly relativethereto lowering said sections.

References Cited by the Examiner UNITED STATES PATENTS Re. 20,653 2/38Lamb 182--l87 2,164,519 7/39 Hayner 182-145 2,340,487 2/44 Paguette182-82 2,9 16,102 12/59 Reinhardt l82143 2,957,582 10/ Lusk 182-144FOREIGN PATENTS 26,109 12/01 Great Britain. 929,545 6/63 Great Britain.

HARRISON R. MOSELEY, Primary Examiner.

REINALDO P. MACHADO, Examiner.

1. A PLATFORM SUPPORTING SCAFFOLD ADAPTED TO SUBSTANTIALLY ENCIRCLE ASTRUCTURE OF GREATER HEIGHT THAN WIDTH AND BE MOVED VERTICALLY RELATIVETHERETO, INCLUDING: (A) A PLURALITY OF GENERALLY RECTANGULAR RIGIDSECTIONS, EACH OF WHICH COMPRISES TWO PARALLEL, LATERALLY SPACEDCOLUMNS, AND REINFORCING MEANS EXTENDING THEREBETWEEN; (B) A PLURALITYOF HORIZONTAL PLATES EXTENDING OUTWARDLY FROM SAID COLUMNS AND BEING OFSUFFICIENT SIZE THAT SAID PLATES ON SAID COLUMNS WHICH ARE MOST ADJACENTTO ONE ANOTHER HAVE PLATE PORTIONS THAT OVERLAP ONE ANOTHER, WITH SAIDOVERLAPPING PLATE PORTIONS HAVING A PLURALITY OF SPACED OPENINGS FORMEDTHEREIN, AT LEAST A PART OF WHICH OPENINGS ARE ALIGNABLE WITH ONEANOTHER; AND (C) A PLURALITY OF ELONGATE RIGID MEMBERS THAT REMOVABLYENGAGE SAID OPENINGS WHICH ARE ALIGNED WITH ONE ANOTHER FOR HOLDING SAIDSECTIONS TOGETHER; (D) SECOND MEANS FOR HOLDING SAID SECTIONS IN SAIDMULTI-SIDED FRAME AT SUBSTANTIALLY FIXED RADIAL DISTANCES RELATIVE TOSAID STRUCTURE; (E) THIRD MEANS FOR DEFINING AT LEAST ONE HORIZONTALPLATFORM; (F) FOURTH MEANS FOR REMOVABLY SUPPORTING SAID THIRD MEANSFROM SAID SECTIONS; AND (G) FIFTH MEANS FOR CONCURRENTLY RAISING ANDLOWERING SAID SECTIONS WHEN DEFINING SAID MULTI-SIDED FRAME RELATIVE TOSAID STRUCTURE TO PERMIT PERFORMANCE OF WORK ON THE EXTERIOR SURFACETHEREOF BY PERSONNEL SUPPORTED ON SAID THIRD MEANS.